Of 4828 registered OHCAs, 3554 (74%) occurred in residential areas. Compared with OHCA in public, individuals with OHCA in private locations were older (70 vs. 62 years, p < 0.0001), more frequently male (76.8% vs. 56.5%, p < 0.0001), more often had arrest during night time (21.2% vs. 11.2%, p < 0.0001), had higher comorbidity rates, experienced longer response time (6.0 vs. 5.0 min, p < 0.0001), were less likely in a ventricular fibrillation (12.8% vs. 38.1%, p < 0.0001), and had a lower survival rate (3.2% vs. 13.9%, p < 0.0001). Demographic characteristics of grid cells predicted OHCA frequency in residential areas. The rate ratios of cardiac arrest in the lowest compared to the highest quartile was: for population density 8.61 (95% confidence interval (CI) 7.25–10.22), for average age 1.80 (95% CI 1.65–1.95), for household income 0.68 (95% CI 0.57–0.81), and for the proportion of short education 1.94 (95% CI 1.68–2.25).